1. Field of the Invention
The present invention relates to an ink jet ink, a method for producing an ink jet ink, an ink jet recording method and an ink cartridge.
2. Related Background Art
An ink jet recording method is a recording method of applying a small ink droplet to any one of recording media such as plain paper, glossy media and the like to form an image, and has become rapidly widespread owing to reduction in its costs and improvement in its recording rate. In addition to the improved quality of the recorded image, and concurrently with the rapid spread of digital cameras, users of ink jet printers now demand to output recorded matter which are comparable to a silver halide photograph.
As a necessary requirement for a recorded matter which is obtained from an ink jet recording method and is comparable to a silver halide photograph, it is cited that both high color developability and durability of the obtained recorded matter are realized simultaneously. Compared with silver halide photographs, a recorded matter obtained from a conventional ink jet recording method has especially low durability, and when exposed for a long period of time to factors such as light, humidity, heat and environmental gases present in the air, the coloring material on the recorded matter would deteriorate. There has been, therefore, a problem in that such recorded matters were susceptible to varying in color tone and fading of the image. In the past various technological improvements have been carried out to resolve this problem.
For example, to improve durability, in particular, light fastness, inks which include a coloring material having an anthrapyridone structure have been proposed (e.g. see Japanese Patent Application Laid-Open 2002-332419 and Japanese Patent Application Laid-Open 2003-192930).